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