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