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