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