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