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