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