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