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