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