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