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