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