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