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