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