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