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