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)(21,22)(23,24)(25,26,31,35)(27,36,39,32)(28,29,40,33)(30,34,38,37)(1,2)(3,7)(4,8)(5,6)(9,10,14,15)(11,12,16,20)(13,21,22,17)(18,24,23,19)(25,27,31,39)(26,32,35,36)(28,37,40,34)(29,38,33,30)(10,15)(11,16)(13,22)(19,24)(25,28,31,40)(26,33,35,29)(27,37,39,34)(30,36,38,32)(1,3,5,4)(2,7,6,8)(9,11)(10,12)(13,18)(14,16)(15,20)(17,19)(21,24)(22,23)(25,28)(26,29)(27,37)(30,36)(31,40)(32,38)(33,35)(34,39)(1,3,5,4)(2,7,6,8)(9,12)(10,16)(11,15)(13,19)(14,20)(17,23)(18,21)(22,24)(25,29)(26,28)(27,38)(30,39)(31,33)(32,37)(34,36)(35,40)(1,4,5,3)(2,8,6,7)(9,13)(10,17)(11,18)(12,19)(14,22)(15,21)(16,23)(20,24)(25,30,31,38)(26,34,35,37)(27,29,39,33)(28,36,40,32)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.