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