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