How to add a discrete list of items to legend in Python?

I need to add an item per raingage to the legend (a different colored dot) in this chart:

I have a discrete list of raingages: 76, 13, 92, 83, 30, 42, 47, 46, 54, 87, 56, 82, 63, 64, 58, 57

This is the my current code:

import plotly.express as px    
fig = px.scatter(df, x="Date", y="Ppt_Depth_In", color="Raingage")
fig.show()

How can I best do this?

three reasons why you should buy plotly pro: support open source, get great support, host your plots and dashboards online