in my opinion it's not supported. You would need to either create all alternative options of images or add more overlays that will foe example grey out some of the nodes etc to indicate they are not yet executed
Is there any possibility we can use the Designer?
since in Designer that comes with JBPM5.4 there is a simulation and also process path highlighting
Maybe just highlight the actual process path will do, but can the designer used outside of guvnor?
if process paths is applicable to your case depends on your requirements which I don't know all of them
designer can be used without guvnor but currently guvnor is the only storage that designer can use so with standalone designer you can model process but you can save it. There is work already in progress to make designer store assets in other way than just guvnor.