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