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