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