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