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