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