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