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