Here is a diagram derivation (mind-map) for a certain cat joke:

txt="A policeman in the big city stops a man in a car with a Siberian Lynx in the front seat. “What are you doing with that Siberian Lynx?” He exclaimed, “You should take it to the zoo.” The following week, the same policeman sees the same man with the cat again in the front seat, with both of them wearing sunglasses. The policeman pulls him over. “I thought you were going to take that cat to the zoo!” The man replied, “I did. We had such a good time we are going to the beach this weekend!”";
LLMResourceFunction["MindMapper"][txt]

Here is a plot corresponding to the obtained Mermaid-JS spec (some tweaking was applied):

ResourceFunction["MermaidInk"][%]

Scope (2)

The second argument can be used to specify the type of diagram:

gr=LLMResourceFunction["MindMapper"][ExampleData[{"Text","Hamlet"}],"characters relationships mind-map"]

Here is the corresponding plot:

ResourceFunction["MermaidInk"][gr]

Here with the third argument we invoke the generation of a more detailed diagram:

gr2=LLMResourceFunction["MindMapper"][txt,"mind-map","between the relationships of the concepts in"]

ResourceFunction["MermaidInk"][gr2]

Possible Issues

Different models produce fairly different outcomes.