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