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