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