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