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