I'm so sorry about your divorce.
As a woman in a similar situation, I can say, you're much, much better served spending your time on taking care of your kids and yourself, than trying to make her suffer.
Nothing can possible make her suffer enough for what she's done, so what's the point? Let it go.
I would not suggest taking them away from their mom totally unless you truly believe she's putting them in danger or is likely to abduct them (even to manipulate you). A very strict supervised visitation agreement would be much better. They need to know their bio mom. I know that hurts but think of all the women who have to let their abusive ex-husbands take the kids for a weekend.
"After all I don't want suffer for her mistakes and let her enjoy her cheating life without an issue."
Too bad. Life is totally unfair and narcissists usually get off easy. The sooner you accept this and focus on your own health and mental well-being, the better. Your mistake (as was mine) was marrying the wrong person. We'll both suffer. My ex has it made: four kids to carry his name, a pittance in child support, two working women suffer the shame of being "single moms" and what is he doing? Sleeping around spreading STDs to even more people.
Que sera sera--if I focused on that, I'd never live.
You are a guy with kids. You are relatively young. Get tested for STDs, spend some time in counseling, and move on. You deserve more than a bitter life spent on getting revenge.