"Do you like the smell of coffee?"
Translation:Houd je van de geur van koffie?
That's grammatically correct, but it sounds very weird to use "leuk" in this context. To describe good sensations (smell, taste or touch), you would always use "lekker" rather than "leuk".
See my comment above. We use "lekker" instead of "leuk" to describe a pleasant smell, taste or sensation.