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