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