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