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