What type of model do you have created from the point cloud? If you are referring to a terrain model in the OpenRoads tools > Terrain Modeling, you can turn on and off the contours through the terrain properties. You control the display through the assigned Feature Definition/Element Template that controls the display.
If you have brought the point cloud information through the Data Acquisition or Survey Processing and exported to the native InRoads DTM or GEOPAK TIN you can use the native tools to display the contours of the surface.
This article goes into detail on importing the point cloud data and generating a terrain model. Then you can use that terrain model or export to the native surface format for display:
This article will show how to assign an element template which is used to control the terrain display if you are keeping the surface information as an OpenRoads Terrain model: