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)(11,12)(13,21)(14,17)(15,19)(16,24)(18,22)(20,23)(25,26,31,29)(27,35,37,32)(28,38,36,33)(30,34,40,39)(1,3,4,7)(2,5,6,8)(9,11,14,19)(10,12,17,15)(13,18,24,23)(16,20,21,22)(25,27,31,37)(26,32,29,35)(28,30,36,40)(33,34,38,39)(1,2)(3,5)(4,6)(7,8)(9,11)(10,15)(12,17)(13,18)(14,19)(16,22)(20,21)(23,24)(25,26,31,29)(27,32,37,35)(28,33,36,38)(30,34,40,39)(9,12,14,15)(10,11,17,19)(13,22,24,20)(16,23,21,18)(25,28)(26,33)(27,30)(29,38)(31,36)(32,34)(35,39)(37,40)(1,3)(2,5)(4,7)(6,8)(9,11)(10,12)(13,23)(14,19)(15,17)(16,22)(18,24)(20,21)(25,29,31,26)(27,35,37,32)(28,33,36,38)(30,34,40,39)(1,2)(3,5)(4,6)(7,8)(9,13,14,24)(10,16,17,21)(11,18,19,23)(12,20,15,22)(25,30)(26,34)(27,36)(28,37)(29,39)(31,40)(32,38)(33,35)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.