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