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