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