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