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