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