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