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