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