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