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