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