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