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)(11,15)(12,14)(13,16)(17,18)(19,20)(21,23)(22,24)(25,26,30,31)(27,28,33,32)(29,34,37,39)(35,36,40,38)(1,3)(2,4)(5,8)(6,7)(9,10)(11,15)(12,14)(13,16)(17,19,22,21)(18,23,24,20)(26,31)(27,33)(29,37)(36,38)(2,6)(3,8)(9,10,12,14)(11,13,16,15)(17,20,22,23)(18,19,24,21)(25,27,30,33)(26,32,31,28)(29,35,37,40)(34,38,39,36)(1,3)(2,7)(4,6)(5,8)(9,10)(11,13)(12,14)(15,16)(17,20)(18,19)(21,24)(22,23)(25,28,30,32)(26,33,31,27)(29,38,37,36)(34,35,39,40)(1,4,5,7)(2,3,6,8)(9,11,12,16)(10,13,14,15)(17,21,22,19)(18,23,24,20)(25,29)(26,34)(27,35)(28,36)(30,37)(31,39)(32,38)(33,40)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.