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