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