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