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