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