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