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