If the topology uses an out-of-band management, it might clutter the drawing.
Here a small topology with an out-of-band management for ovs-1, ovs-2 and ovs-3. Even in this small topology the management network is distracting.
To hide the management network I added a rectangle and lowered its layer (right-click, "Lower one layer"). Additionally I lowered the layer of Switch1. That way the links to Switch1 are put into a layer below the rectangle.
This hides the management links, but the border of the rectangle is disturbing.
Select the rectangle and open the style dialog (right-click, Style). Here you can set the border style to "No border". Optionally you can set the fill color to an opacity of 80%, this gives a faint view of the underlying network.
If you need full access to the management layer, lower the rectangle by one more layer. Alternatively you can raise the Switch1 by one layer.