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