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