How do you feel about animating the computation in the digraph? graphviz allows for custom ids in nodes and edges. These could be used to encode, target and modify the transitions in the SVG.

Hi Fabian, thanks for the idea! I'd thought initially about creating an animated digraph to show the computation path along the states, but I decided to focus first in implementing the functions to run the Turing Machine and in a visualization to see the evolution of the tape and the movement of the machine's head. I will try to animate the digraph later. If you fork the notebook and make something cool in this way, please let me know! I need to study more about how to do animation with d3 and Observable.