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)(26,29)(27,35)(28,38)(34,40)(1,2,5,3)(4,6,8,7)(9,11,15,22)(10,16,20,23)(12,18,14,21)(13,19,24,17)(25,26,31,29)(27,36,35,32)(28,39,38,33)(30,34,37,40)(2,3)(6,7)(9,12,15,14)(10,17,20,19)(11,21,22,18)(13,16,24,23)(25,27)(26,32)(28,37)(29,36)(30,38)(31,35)(33,40)(34,39)(1,3,5,2)(4,7,8,6)(9,13,15,24)(10,18,20,21)(11,17,22,19)(12,23,14,16)(25,28,31,38)(26,33,29,39)(27,37,35,30)(32,40,36,34)(9,14,15,12)(10,19,20,17)(11,21,22,18)(13,16,24,23)(25,29,31,26)(27,36,35,32)(28,39,38,33)(30,40,37,34)(1,4)(2,6)(3,7)(5,8)(9,10)(11,16)(12,17)(13,18)(14,19)(15,20)(21,24)(22,23)(25,30,31,37)(26,34,29,40)(27,38,35,28)(32,39,36,33)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.