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