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