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