It is possible to configure CMDB visualizer information?
I Want to show, for example the CI class in mouseover.
It is possible?
You can't change the mouse-over information. See this knowledge document:
Visualizer design and customization limitations - CA Knowledge
You may wish to vote/comment for this Idea which has been Wish-listed, which might support such features:
Rebuild of CMDB Visualizer on modern technology like HTML5