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