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