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