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