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