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