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