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)(13,14,17,20,18,21,16,27)(15,22,26,28,25,24,23,19)(5,6)(7,11)(8,10)(9,12)(13,15,18,25)(14,19,21,28)(16,26,17,23)(20,24,27,22)(1,2,3,4)(5,7)(6,9)(8,12)(10,11)(13,16,18,17)(14,20,21,27)(15,23,25,26)(19,22,28,24)(7,12)(9,11)(13,14,16,27,18,21,17,20)(15,24,23,28,25,22,26,19)(6,10)(9,11)(14,21)(15,25)(20,27)(23,26) 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.