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