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