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