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