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