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