If the map initially doesn't appear, your profile may have be set to indicate that you don't want to participate in the Parent Map. First, make sure that the 'Opt In' box is ticked in the 'My Profile' section.
If the problem persists, you should also consider trying to open the page using a different browser. When using Classlist on Internet Explorer 11, the feature will often not appear at all.
Please contact your class rep or firstname.lastname@example.org if you're still unable to view the map having tried the approaches above.