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