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