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)(11,15)(12,20)(13,14)(16,22)(17,19)(18,24)(21,23)(25,26)(27,30)(28,35)(29,32)(31,36)(33,39)(34,38)(37,40)(1,3,6,4)(2,7,5,8)(9,10)(11,17)(12,16)(13,14)(15,19)(18,24)(20,22)(21,23)(25,27,29,34)(26,30,32,38)(28,33,36,40)(31,37,35,39)(10,14)(15,17)(16,20)(23,24)(25,26,29,32)(27,30,34,38)(28,31,36,35)(33,37,40,39)(1,3,6,4)(2,7,5,8)(9,10)(11,15)(12,16)(13,14)(17,19)(18,23)(20,22)(21,24)(25,26)(27,30)(28,31)(29,32)(33,37)(34,38)(35,36)(39,40)(1,4,6,3)(2,7,5,8)(9,11)(10,15)(12,21)(13,19)(14,17)(16,24)(18,22)(20,23)(25,27)(26,30)(28,33)(29,34)(31,37)(32,38)(35,39)(36,40)(1,5,6,2)(3,8,4,7)(9,12)(10,16)(11,18)(13,22)(14,20)(15,23)(17,24)(19,21)(25,28,29,36)(26,31,32,35)(27,33,34,40)(30,37,38,39)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.