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