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