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