Element("Shape", {"ID": "100", "name": "Process", "type": "Shape"}

Where is this shape coming from? Normally with Visio you need to have a stencil open and reference a shape master within that stencil.

On top of that a shape that has been added to a page needs to have a height and width, as well as X and Y coordinates.

Also you have no line style, the shape might be being created but invisible against the background.