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