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