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)(13,14)(15,22)(16,25)(17,20)(18,21)(19,27)(23,28)(24,26)(5,7)(6,9)(8,12)(10,11)(13,15)(14,20)(16,26)(17,18)(19,24)(21,22)(23,27)(25,28) involution — undirected(6,10)(9,11)(13,16,25,14,18,27,19,21)(15,23,28,22,17,26,24,20)(7,12)(9,11)(13,17,18,15)(14,20,21,22)(16,26,27,23)(19,28,25,24)(1,3,4,2)(6,10)(9,11)(14,21)(15,17)(16,27)(24,28)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.