UVs are viewed and edited in the 2D view of the UV Editor (UV > UV Editor). UVs display whenever a polygonal or subdivision surface mesh is selected in the scene view. When the 3D mesh is de-selected the UVs are no longer displayed in the UV Editor.
By default, all of the UVs for a selected object get displayed. You can display a subset of UVs using the Isolate Select feature. For more information see Display a subset of UVs.
The 2D representation of UVs cannot be displayed in the Maya scene views.
To display UVs in the UV Editor
The UV Shells for the selected mesh are displayed in the UV Editor.
The UVs associated with the vertices you selected on the mesh are displayed in the UV Editor.