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