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