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