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