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