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