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