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