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