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