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