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