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