As with any meeting, do it slowly. Let the ferret get settled in for a couple of days before doing introductions. You might also want to put a towel where the cat sleeps so his odor is on it and place it with the ferret so he gets use to his sent. When doing introductions, have one person hold the ferret and one person hold the cat. Let them sniff each other but keep the intros short. Do NOT let the fert run around on the ground until you are certain the cat does not have a high prey drive.
I know when I had my 4 ferts that they loved everyone and everything and pretty much ruled the household. Most ferts have no fear of anything, but a deaf one may be different. I had a couple of ferts who enjoyed playing with my dog. It was really funny to watch. Both cats and dogs had respect for the ferts and never thought of them as prey.
Here was Stretch being checked out by Salem and Taz
These were my 3 girls - Snow White, Sunshine and Ashley
Taz trying to explain that this is a C A T tree
Snow White enjoyed playing with Indy and would jump up and grab his fur.
Just take it slowly and they will probably become the best of friends. I would love to see pics of the 2 of them together.