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