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