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