Depends on your sink. But you should be able to unscrew the little screen at the end of the faucet. When I had a waterbed back in the day, there was this little plastic adapter i got from the waterbed store. One end screwed into the faucet (after you unscrew the screen) and the other end was designed to have a hose screwed on it.
Not sure if regular stores or hardware stores would sell it, but def check a place that sells waterbeds, they should have it.