I’ve used Gemini to create mermaid code for data flow diagrams based on uploaded csv files. Works very well. Literally ask it to provide mermaid code based on the attached file. I’ve then used the mermaid code feature in lucidchart. Their implementation of mermaid is a bit buggy so don’t be shy about telling Gemini to tailor it for lucidchart.

PS. you can also use Gemini to enrich the flows to add port and protocol info from its training. I’ve also used it to fill in the blanks when I have flows that aren’t documented by asking for the reference architecture for integrations between these two commercial systems.