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