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