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