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