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