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