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