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)(11,18)(12,15)(13,17)(14,16)(19,24)(20,22)(21,23)(25,26,31,35)(27,32,36,39)(28,33,38,37)(29,30,34,40)(3,4)(6,8)(9,11,15,14)(10,16,12,18)(13,21,22,19)(17,24,20,23)(25,27)(26,32)(28,30)(29,37)(31,36)(33,34)(35,39)(38,40)(1,3,5,4)(2,6,7,8)(10,12)(16,18)(17,20)(23,24)(27,36)(28,38)(32,39)(33,37)(3,4)(6,8)(9,12,15,10)(11,18,14,16)(13,17,22,20)(19,23,21,24)(25,28)(26,33)(27,30)(29,39)(31,38)(32,34)(35,37)(36,40)(1,4,5,3)(2,6,7,8)(9,13,15,22)(10,17,12,20)(11,19,14,21)(16,23,18,24)(25,29)(26,30)(27,37)(28,32)(31,34)(33,36)(35,40)(38,39)(1,2)(3,6)(4,8)(5,7)(9,14,15,11)(10,18,12,16)(13,19,22,21)(17,23,20,24)(25,30)(26,34)(27,28)(29,35)(31,40)(32,33)(36,38)(37,39)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.