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