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