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