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