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