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