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