Adding numbers and characters to legend key in ggplot2 of UMAP clusters

Question

[Michael]

Hi everyone,

I have a UMAP cluster, however there are so many clusters that the descriptions look clunky if i put them on the umap...but then there are too many colors if it just colors. So, i would like to have numbers on the chart and also on the legend (with the text) as this example:

I think it has to do with override.aes, but I can't quite figure it out. Any help?