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