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