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