first of all, part of this issue is probably genetic. we're all known guys, since back when we were in highschool, that seemed to have great abs all the time with little or even no work. some of this probably comes down to how they store body fat and some comes down to the shape of their ab muscles. these are things you can't effect, but that doesn't mean you that you can't have visable abs. it may just take more work. 

i'm pleased to see that you've posted this question in the "diet and nutrition" section. that leads me to beleive that you are on the track. abs are created in the kitchen, more than in the gym. we all have abdominal muscles, its just a matter of getting them out! if you are eating any dairy, start by cutting that out. all of it. next, make sure your carbs are coming from clean, slower burning sources. no starches, stick with brown rice, yam, and oat. i prefer steel cut oats. your first meal of the day, as well as pre and post training meals are the best places to take in your carb meals. over time, you may find you need to lower your carbs to acheive the look you desire. for protein, i would suggest moving some of your meals to a tilapia or cod instead of chicken. i wouldn't go to eating all fish right away, but i would slowly go that direction. make sure you're getting a lot of water. drinking water will push fluid out of your body. holding fluid in your midsection will cover of your abs. on the note of fluid retention, eat a consistent amount of sodium. going up and down with sodium will make you hold fluid, but if you stay consistent, your body will be less likely to hold extra water. 

for your cardio, i would certainly do more. when dieting, i start with 30 min, 5x wk. the best time to do your cardio is first thing in the AM fasted, before you eat your first meal. over time, i add more cardio, slowly building up the time as my body gets used to the amount of cardio i'm doing. eventually, i do two sessions. one fasted session and one session post workout before eating anything. if you can't do cardio AM fasted, do it post workout. by the end of a diet, i have bulit my cardio up to 2 sessions a day, 7 days a wk. never go over an hour per session. use the step mill or the treadmill keeping your heart rate 120-130. 

early on, it took a lot of work to get my abs to look good. part of that was that my abs were shallow. over time (years), the muscle has thickened and become easier to unveil. i consistently train abs every other day for about 8-10 minutes after training. the more dense your abs become, the easier they will show. i would suggest staying away from twisting moves that will thicken your obliques and give your waist a wider look.

best of luck bro!