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