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