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