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