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