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