Adding on, just because the question asks about the causes doesn’t mean you can’t use the graphs above. As part of the explanation of the causes, you’d have to go through basic definitions and explanations, and also talk about the effects of unemployment (tying it into recent trends).
The Short Run Phillips Curve (trade off between unemployment and inflation) and Long Run Phillips Curve (trying to reduce cyclical unemployment beyond NAIRU) can both be used in conjunction with discussion about cyclical unemployment or trends.
The Keynesian Deflationary Gap (see the Diagrams Compilation post I made on this board) can also be used to show how unemployment exists macroeconomically.
The diagrams don’t have to relate exactly to the causes, as long as you can tie it in to something relevant