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