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