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