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)(13,14,19,21,18,23,17,22)(15,20,26,27,16,25,24,28)(1,2)(3,4)(5,6)(7,11)(8,10)(9,12)(13,15)(14,20)(16,18)(17,24)(19,26)(21,27)(22,28)(23,25) involution — undirected(5,7,8,12)(6,9,10,11)(14,21)(17,19)(20,27)(22,23)(24,26)(25,28)(2,4)(7,12)(9,11)(13,16,18,15)(14,20,23,25)(17,26,19,24)(21,27,22,28)(6,10)(9,11)(15,16)(20,25)(24,26)(27,28) 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.