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