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