I'm not an expert in this, but I believe you can used dashed or broken lines to cover elements of the design that aren't to be covered by the patent. This is a good article explaining this. Based on this, I think you would draw the plug portion of your figures in broken lines. Here is the USPTO guide. There is a section there about broken lines:
Broken Lines
A broken line disclosure is understood to be for illustrative purposes
only and forms no part of the claimed design. Structure that is not
part of the claimed design, but is considered necessary to show the
environment in which the design is used, may be represented in the
drawing by broken lines. This includes any portion of an article in
which the design is embodied or applied to that is not considered part
of the claimed design. When the claim is directed to just surface
ornamentation for an article, the article in which it is embodied must
be shown in broken lines.
In general, when broken lines are used, they should not intrude upon
or cross the showing of the claimed design and should not be of
heavier weight than the lines used in depicting the claimed design.
Where a broken line showing of environmental structure must
necessarily cross or intrude upon the representation of the claimed
design and obscures a clear understanding of the design, such an
illustration should be included as a separate figure in addition to
the other figures which fully disclose the subject matter of the
design.