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