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