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