By looking at the source of your webpage, I don`t think the google maps with driving directions plugin is installed. This plugin requires Jomres v4.2 or above
Configuration can be made from the backend (admin) where a new button was created after you installed the plugin. Here you can set map width and height to fit your template, map zoom level, map type and choose if you want to display driving directions or not.
For this plugin to work, it is mandatory that you enter latitude and longitude coordinates for your properties. Also, please make sure that google driving directions feature is supported for your country.
If you`ve done all this and the map still not shows up, then try the default joomla template, see if this way the map will show up.