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