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