One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,8)(4,6)(5,7)(9,10)(11,17)(12,15)(13,16)(14,19)(18,23)(20,22)(21,24) involution — undirected(9,11,13,19)(10,14,16,17)(12,18,20,24)(15,21,22,23)(26,30)(27,33)(28,36)(31,37)(32,34)(35,39)(1,3,5,4)(2,6,7,8)(9,12,13,20)(10,15,16,22)(11,18,19,24)(14,21,17,23)(25,26,28,30,29,31,36,37)(27,34,33,40,35,32,39,38)(10,16)(14,17)(15,22)(21,23)(26,31)(30,37)(32,34)(38,40) involution — undirected(1,4,5,3)(2,6,7,8)(11,19)(14,17)(18,24)(21,23)(25,27,28,33,29,35,36,39)(26,32,30,38,31,34,37,40)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.