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