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