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