One vertex per element, one color per generator, with an edge from x to x·s.
(2,3)(5,6)(7,10)(8,9)(11,12) involution — undirected(1,2,4,3)(6,9)(10,12)(13,14)(15,22)(16,18)(17,21)(19,25)(20,26)(23,27)(24,28)(1,3,4,2)(5,7,8,11)(6,10,9,12)(14,18)(15,23)(16,26)(19,22)(20,21)(24,25)(13,15)(14,19)(16,24)(17,25)(18,27)(20,28)(21,22)(23,26) involution — undirected(14,18)(15,24)(16,26)(20,21)(23,25)(27,28) 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.