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