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