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