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