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