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