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