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