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