Static illustrations are ubiquitous means to represent interaction scenarios. Across papers and reports, these visuals demonstrate people's use of devices, explain systems, or show design spaces. Creating such figures is challenging, and very little is known about the overarching strategies for visually representing interaction scenarios. To mitigate this task, we contribute a unified taxonomy of design elements that compose such figures. In particular, we provide a detailed classification of Structural and Interaction strategies, such as composition, visual techniques, dynamics, representation of users, and many others-all in context of the type of scenarios. This taxonomy can inform researchers' choices when creating new figures, by providing a concise synthesis of visual strategies, and revealing approaches they were not aware of before. Furthermore, to support the community for creating further taxonomies, we also provide three open-source software facilitating the coding process and visual exploration of the coding scheme.