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