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