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