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