Nonacademic Letter of Recommendation for Masters
it depends on the university, for instance on my university the hierarchy of letter of recommendations goes like this:


Top priority: Faculty (same/different institution)
Mid: Staff (on same institution)
Low: High-school Instructors


Of course having faculty give you letters of recommendation is better.
Just remember that "usually" you need 2-3 letters of recommendation.

I would suggest to use the letter of recommendation from this director that you mention, If and only if you cant get letters of recommendations from faculty.