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