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)(18,24)(22,23)(25,26,30,33)(27,34,28,31)(29,32,38,37)(35,40,36,39)(1,2)(3,4)(5,7)(6,8)(10,15)(12,23)(16,19)(18,21)(25,27,30,28)(26,31,33,34)(29,35,38,36)(32,39,37,40)(1,3)(2,6)(4,7)(5,8)(10,15)(11,20)(12,23)(13,24)(25,26,30,33)(27,31,28,34)(29,37,38,32)(35,40,36,39)(3,8)(4,6)(9,11,14,20)(10,16,15,19)(12,18,23,21)(13,22,24,17)(25,26)(27,31)(28,34)(29,32)(30,33)(35,39)(36,40)(37,38)(1,4)(2,3)(5,6)(7,8)(9,12,14,23)(10,17,15,22)(11,21,20,18)(13,16,24,19)(25,28,30,27)(26,31,33,34)(29,36,38,35)(32,39,37,40)(1,2)(3,4)(5,7)(6,8)(9,13,14,24)(10,18,15,21)(11,22,20,17)(12,16,23,19)(25,29,30,38)(26,32,33,37)(27,35,28,36)(31,39,34,40)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.