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