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