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