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