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