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