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