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