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