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