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