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)(11,16)(12,14)(13,15)(17,18,21,24)(19,22,20,23)(25,26)(27,31)(28,32)(29,35)(30,33)(34,39)(36,37)(38,40)(2,6)(4,8)(9,11)(10,12)(13,14)(15,16)(25,27,30,35)(26,31,33,29)(28,36,38,34)(32,37,40,39)(9,12)(10,14)(11,15)(13,16)(17,19,21,20)(18,22,24,23)(25,27)(26,29)(28,34)(30,35)(31,33)(32,37)(36,38)(39,40)(1,3)(2,4)(5,7)(6,8)(9,12)(10,11)(13,16)(14,15)(17,18)(19,22)(20,23)(21,24)(25,28,30,38)(26,32,33,40)(27,34,35,36)(29,37,31,39)(1,4)(2,7)(3,6)(5,8)(9,10)(11,16)(12,14)(13,15)(17,20,21,19)(18,23,24,22)(25,29)(26,27)(28,37)(30,31)(32,34)(33,35)(36,40)(38,39)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.