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