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