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