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