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