Visibility Options

Right-click on Displacement in a subcase and select Edit. Click on the Visibility Options tab and the form looks as shown in the figure below.

These options allow you to switch the symbols or highlighting on and off using the flip button:

You can also control visibility of these items by clicking Display Object Visibility in the Autodesk Inventor Nastran ribbon tab and activating/deactivating the individual items from there. See the Object Visibility page for more information.