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