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