Can I apply to CS graduate programs and take a year off before actually enrolling?
As keshlam truly mentioned, you need to check the existence of any deferral plan for that program.

If your admitted position would be a course-based one (like MEng), the deferral possibility would be applicable, noticeably. But in the case of the research-based programs (like M.Sc., M.A.Sc., Ph.D. and so on), the deferral chance might not be high, because such positions are often defined based on the funding, provided by either industrial or governmental customers and would not be postponed, considerably. If so, you have to reconsider to apply.