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