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