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