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