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