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