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