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