Hello @MEDOW!
I assume you would like to have the mean values displayed in your graphs and not as summary statistics below the graph.
If you would like to see the means in the graph, a way of doing that is going to Graph Builder, Select your Y and X factors, Select Box Plot (customize whatever color/style you want), right click on one of the points --> points --> summary statistics --> mean, you'll now have only one point indicating the mean, to show mean values: in the "points" menu (bottom right corner) --> change label from "no labels" to "label by value".
See an example of this in the attached picture.
Hope this helps!
Manlio