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