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