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