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