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