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