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