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