Hi Michelle,
I don't have a template; however, I've been in the habit of taking photos of activities/events/classes in the library and popping them into folders by month each year. I often have a student volunteer pop the photos into a video (in recent years using Canva). If I carefully label/organize the photos throughout the year with good file names within the month folders, a student can use those names to write captions for the photos in the video. I try to also include statistics such as circ stats, classes taught, etc. The video can serve as an important advocacy tool. Keep it as short as possible so people will watch it. It can also be used to show new or current faculty some of what can happen in the library.
I'm sure someone out there has a good one-pager type infographic which are great too.