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