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