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