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