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