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