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