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