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