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