Can I set up my "new " Olympus OM5 to show taken image on LCD screen?

Not sure what you mean by the "menu board", but John Bean is right, you can have the picture play back for however many seconds after it is taken by setting the rec view time under the wrench menu. Maybe what you are referring to is that in  playback the  picture shows with whatever overlay information you have set for the play mode. Go into play mode on a picture, then press "info" to change the info shown during playback. You can control what views are shown deeper in the menus. Maybe you prefer the view with no overlay, for example. That is the view that will be used in the review mode after a picture is taken; it is just like you had pressed the play button.