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