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