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