To diagnose signs of a cheating husband requires a lot of efforts from you, being a wife. Normally, cheating husbands are quite aware of the things with which their infidelity might get discovered. So, they being enough smart try their best to leave no stone unturned. And that is the reason why you will have to be extra cautious of what he is up to.
I know, this is not an easy job but there is no other alternative to such a situation. You cannot let this shameful thing happen for long in front of your eyes. If your cheating husband cannot live up to his marriage vows, then who the hell insisted him to get into such a sacred relationship.