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