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