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