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