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