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