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