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