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