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