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