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)(15,23)(16,21)(17,22)(18,27)(19,25)(20,26)(24,28)(1,2)(3,4)(6,9)(7,11)(13,14,16,21)(15,24,25,20)(17,27,18,22)(19,28,23,26)(6,9)(10,12)(13,15)(14,19)(16,25)(17,28)(18,26)(20,22)(21,23)(24,27) involution — undirected(2,4)(5,7,8,11)(6,10,9,12)(13,15)(14,20)(16,25)(17,26)(18,28)(19,22)(21,24)(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.