I struggled with this issue on my hybrid.

I ended up borrowing the neighbors skinnier Trek bike seat. She thinks that it was a cheap seat. It made a world of a difference. So, if at all possible, try out different seats.

Also, make sure the rest of the bike fits you right. Other things off may effect the comfort of the seat. I experimented with moving handlebars up and down and changing the angle. I did the same with the seat. In my case, no matter what the seat was bad. Then I tried the different seat.