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