Hi Victor.
In order to see the diagram, you have to import to guvnor not only the process definition, but the exported image. This image has to be named <<ProcessID>>-image.png. For example, if you have your process:
<process processType="Private" isExecutable="true" id="MyTest" name="MyTest" tns:packageName="test" >
You have to import an image to guvnor called MyTest-image.png.
Nowadays, the console only gets images from the defaultPackage (https://issues.jboss.org/browse/JBPM-3277).
Hope it helps!
Demian