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