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