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