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