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