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