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