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