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