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