What do I need to do differently to get my 6 pack to show through my stomach?

I have a thin layer of fat covering my abs. I watch what I eat making sure I get a lot of protein. Schedule my workouts around meals. I do an ab/pushup workout in the morning then a weights workout with some abs in the afternoon. At night I do another ab/pushup workout. I do cardio every other day. My ab/pushup workout consists of 160 pushups and 280 varied situps for each session.(so 320 pushups and 640 situps a day) I workout 6 times a week. my weights workout in the afternoon lasts an hour.