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