One vertex per element, one color per generator, with an edge from x to x·s.
(6,10)(7,8)(11,12)(15,21)(16,23)(18,26)(20,24)(22,25)(27,28) involution — undirected(1,2)(3,4)(5,6,9,11)(7,10,8,12)(13,14)(15,18)(16,24)(17,19)(20,23)(21,28)(22,27)(25,26)(2,4)(5,7,9,8)(6,10,11,12)(13,15)(14,18)(16,25)(17,22)(19,27)(20,28)(21,23)(24,26)(14,19)(18,27)(20,24)(26,28) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.