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