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