The faculty club is on the East side of campus at the same level as the Cal Stadium.

Public Parking is available on weekends in the Bancroft lot or in a the Boalt lot just a few hundred feet south east of the Faculty Club: http://www.google.com/maps/ms?ie=UTF8&hl=en&msa=0&msid=10042043183639845...

This page will generate directions:
http://www.berkeleyfacultyclub.com/piedmont/

although I find the directions to the building next to it more helpful:
http://www.womensfacultyclub.com/direction.html