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