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