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