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