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