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