He needs to be the aggressor. Cain's game is relentless, varied pressure. If JDS does the same and just tries to counter, he'll be spending most of the fight defending TD's and getting back to his feet, which makes it extremely difficult to get any sort of striking going not to mention allows Cain to surprise him with strikes because he's always worried about going for a ride.
With that sort of intensity and wrestling, it will be difficult for him because he's predictable. You never know whether Cain is going to punch you in the face, take you down, pin you against the cage or a combination of all the above. How do you fight against that? Do what Cain did, pile on the pressure and hurt him before he has a chance to get going.
JDS would be better of wading in throwing bombs and just accept that takedowns will come, because to his credit he is impossible to keep down. Cain will be far less willing to exchange if JDS is being really aggressive and hurting him.
Then he needs to hope Cormier drops to LHW because he would be as problematic.