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