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