You can go to Software and Updates>Additional Drivers tab and select one from there. See example screenshot in this post: Install a more updated Nvidia driver - #2 by StarTreker
You may need to research which is the best driver for your specific Nvidia graphics card. If you can tell us which Nvidia graphics you have, someone here may be able to help suggest one for you.
EDIT: Also note Z17.1r2 is now being released by the devs with later Nvidia drivers. See: Zorin OS 17.1 r2