On a more serious note.
The best thing that you can do is write an article for the work intranet / staff mag or the infoboard with a little story about how you got your licence. Go on then to explain a little about what the PPL is and about how everyone on a private flight such as you make simply share the costs and how this can be great for everyone involved. Make sure you finish with a note explaining where you fly from the number of seats in the aircraft you fly and roughly how much it costs to fly various places.
All simply a factual article of interest to some people in the organisation. Not a case of advertising.
Regards,
DFC