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