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