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