  We study the boundaries of the positroid cells which arise from N = 4 super
Yang Mills theory. Our main tool is a new diagrammatic object which generalizes
the Wilson loop diagrams used to represent interactions in the theory. We prove
conditions under which these new generalized Wilson loop diagrams correspond to
positroids and give an explicit algorithm to calculate the Grassmann necklace
of said positroids. Then we develop a graphical calculus operating directly on
noncrossing generalized Wilson loop diagrams. In this paradigm, applying
diagrammatic moves to a generalized Wilson loop diagram results in new diagrams
that represent boundaries of its associated positroid, without passing through
cryptomorphisms. We provide a Python implementation of the graphical calculus
and use it to show that the boundaries of positroids associated to ordinary
Wilson loop diagram are generated by our diagrammatic moves in certain cases.
