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