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)(11,16)(12,14)(13,23)(15,19)(17,22)(18,20)(21,24)(25,26,31,34)(27,35,30,32)(28,33,39,29)(36,40,38,37)(1,2)(3,5)(4,6)(7,8)(9,11,15,21)(10,16,19,24)(12,20,22,13)(14,18,17,23)(25,27,31,30)(26,32,34,35)(28,38,39,36)(29,37,33,40)(9,12,15,22)(10,17,19,14)(11,13,21,20)(16,18,24,23)(25,28)(26,33)(27,36)(29,34)(30,38)(31,39)(32,37)(35,40)(9,12)(10,14)(11,20)(13,21)(15,22)(16,18)(17,19)(23,24)(25,29,31,33)(26,28,34,39)(27,37,30,40)(32,38,35,36)(1,3,4,7)(2,5,6,8)(9,13,15,20)(10,18,19,23)(11,12,21,22)(14,16,17,24)(25,28)(26,33)(27,38)(29,34)(30,36)(31,39)(32,40)(35,37)(9,14)(10,12)(11,18)(13,24)(15,17)(16,20)(19,22)(21,23)(25,30,31,27)(26,32,34,35)(28,38,39,36)(29,40,33,37)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.