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