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