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