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