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