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