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