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