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