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