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