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