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