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