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