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