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