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