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