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