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