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