What kind of graph?
Proc summary/means will create summary statistics and create a data set that maybe can be graphed but it depends on the type of graph that you want.
Best would be to provide an example data set or use one of the data sets in the SASHELP library and then describe what you want.
The type of graph is important as that will lead to how the input data needs to be structured.
Consider that Proc SGPLOT can create 27 different types of plots, with some variations for some of those, and that most of these can be overlayed to create additional interpretations we really need to know.
Or you can look here for some examples of different graphs, the data and code to make them: https://support.sas.com/en/knowledge-base/graph-samples-gallery.html
Start by looking at SGPLOT and SGPANEL. Much more complicated graphs can be made with SGRENDER and the Graphic Template Language.