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