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