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