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