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