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