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)(13,14,20,17,18,23,19,24)(15,25,27,16,22,21,28,26)(6,9)(10,12)(13,15)(14,21)(16,24)(17,26)(18,22)(19,28)(20,27)(23,25) involution — undirected(2,4)(5,7,8,11)(6,10,9,12)(13,16,18,26)(14,22,23,15)(17,28,24,27)(19,25,20,21)(6,9)(10,12)(13,17,20,23,18,24,19,14)(15,26,27,25,22,16,28,21)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.