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