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