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