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