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