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