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