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