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